1. Field of the Invention
This invention relates to a quick-connect mechanism for receiving tools and tool bits, the mechanism being embodied in a holder which it turn may be mounted, permanently or removably, in a driving tool such as a power drill for example, or a hand tool such as a screwdriver for example.
2. Description of the Prior Art
Traditional quick-connect mechanisms for connecting tools to a holder are shown in, for example, U.S. Pat. No. 5,779,404 (Jore). This mechanism has the apparent drawback of not allowing an operator to insert and release the tool using only one hand (the other hand would be used to grip the power tool or hand tool which would power the tool/holder), necessitating the sleeve to be retracted manually to release the tool from the holder.
It is an object of the invention to provide an improved holder for tools or tool bits such as drill bits, screwdriver bits or the like, the holder being simple to produce and assemble, and yet performing the required functions well.
The invention provides a holder which has a quick-connect mechanism actuated by inserting a bit, the bit engaging means to force retraction of a collar, where the collar actuates means for engaging the bit, and released by manual retraction of the collar, whereby the tool bit is release from the holder.
In the invention, a holder for holding a tool bit comprises an elongate connector means attachable to a power tool/hand tool, the connector having a longitudinal hole with a cross-section corresponding to the cross-section of a mounting portion of the tool bit. The connector means further includes a first radial hole running from an outside surface of the connector to the longitudinal hole, the first radial hole having a large diameter bore portion at the outside surface of the connector and a small diameter bore portion at the longitudinal hole, and a substantially truncated hemispherical shape. A substantially spherical locking ball is movably arranged in the first radial hole, cooperating with the substantially truncated hemispherical shape of the first radial hole, where the locking ball cooperates with a circumferential groove in the tool bit to lock the tool bit in place when the tool bit is fully inserted into the holder. An outer sleeve is arranged to reciprocally slide over the first connector between two end positions. The outer sleeve has a first end facing the tool bit and a second end facing the tool mount. The connector means is attachable to a power tool or hand tool via a tool mount. The outer sleeve has a stepped inside diameter, having a smaller diameter part facing the power tool or hand tool, and a larger diameter part facing the tool bit. A bevelled transition is arranged between the two different diameter parts, the bevelled transition is arranged to cooperate with a transition ball. A sleeve biasing means, for example a coil spring, is arranged to bias the sleeve away from the tool mount. The transition ball is arranged in a transition hole in the connector means. The transition hole is substantially radial, and preferably, but not necessarily, angled so that the bottom of the transition hole is arranged further from the tool mount than the top of the transition hole. Alternatively, the transition hole is substantially perpendicular to the longitudinal hole. Thus, the transition ball, which has a diameter substantially corresponding to the diameter of the transition hole, is slidable between a first position at the bottom of the transition hole, to a second position protruding from the top of the transition hole. The bevelled transition is pressed against the transition ball by the sleeve biasing means.
The sleeve is held in its end positions by a mechanism comprising a locking cavity, which cooperates with a locking ring arranged in a locking ring groove arranged on the elongate connector means, to limit the stroke of the sliding movement of the sleeve along the elongate connector means in the direction towards the tool mount or handle by the locking ring blocking further movement because the locking ring contacts the edge of the locking cavity, and in the direction towards the tool bit by the bevelled transition contacting the transition ball in its position at the bottom of the transition hole, which protrudes enough to block the movement of the sleeve when the bevelled transition contacts the larger diameter portion of the elongate connector means. In the latter position, the sleeve is prevented from sliding towards the tool mount or handle, under the biasing influence of the biasing means, by the frictional forces present between the inside of the sleeve and the locking ring.
When the tool bit is inserted into the longitudinal hole, the inserted end of the tool bit will push the transition ball radially outwards in the transition hole. The transition ball is pressed by the inserted end of the tool bit, from its position at the bottom of the transition hole towards the sleeve and the bevelled transition, thus pressing the sleeve towards the tool mount or handle. A locking portion of the sleeve effectively blocks the locking ball from movement in the first radial hole, locking the tool bit in the longitudinal hole.
In a further embodiment of the invention, the sleeve has a locking cavity, which cooperates with a locking ring arranged in a locking ring groove arranged on the elongate connector means to limit the stroke of the sliding movement of the sleeve along the elongate connector means, by either edge of the locking cavity contacting the sides of the locking ring to provide the blocking of the sleeve. The outer sleeve is arranged to reciprocally slide over the connector means between two end positions, and has a stepped inside diameter, having a smaller diameter part facing the tool mount and a larger diameter part facing the tool bit. A middle diameter part is arranged between the smaller and the larger diameter parts, having a diameter which is larger than the diameter of the small diameter part but smaller than the diameter of the large diameter part. The middle diameter part is arranged to house a sleeve biasing means. A bevelled transition is arranged between the large and middle diameter parts. The bevelled transition functions similarly to the bevelled transition described for the earlier embodiment, in cooperation with a transition ball.
Further features of the invention will be described or will become apparent in the course of the following detailed description.